Sunday, October 19, 2014

Fetishizing the Moog modulars

Lately I'm noticing a big surge of
interest in the vintage modular Moogs. Now, this in itself is not a
bad thing. It's a good thing, and not only from the historical preservation sense. It's always good to have a perspective of history, and to see
how Bob Moog and his compatriots made their decisions and went about
doing things without access to all of the technology we have today.
Remember, in 1963 when Moog and Buchla built their first modules, the
integrated circuit was still largely confined to Fairchild Semiconductor's labs.
The commercially package operational amplifier was a big ugly box
that plugged into a tube socket and contained a pair of 12AX7 tubes
inside it. There were no OTAs, no 4000 CMOS logic; Doug Curtis was
in elementary school, and Ron Dow had not yet gone to Dave Rossum
and Scott Wedge to beg for money (which was a good thing, since
Rossum and Wedge were themselves high school students and didn't have any
money).

Yes, things were different back then.
Moog (and, independently, Buchla) had just thought of the idea of
“voltage control”, in which he imagined that a generated signal
might be able to remotely control the functioning of another circuit,
thereby increasing the possibilities for more animation in electronic
music, e.g., that the output of one oscillator could control the
frequency of another in order to introduce vibrato, without a person
having to constantly turn the frequency knob up and down. This was
new territory; at first Moog had no idea how to do it with components
that were available to him. As he attacked the problem, he made it
work, but there were a lot of compromises: many components being made
to do things that they weren't designed to; use of some expensive
components which forced cost cutting in some other areas, and the
necessity to keep the circuits confined to a reasonable sized
package. There were also things to consider like what we now call
the “user interface” was to function. (We all know the story of
how the synthesizer came to be primarily a keyboard instrument: the
switches of an organ keyboard, wired to a resistor grid, worked a lot
better than primitive pitch-to-voltage converters and provided an
interface that looked familiar to musicians.)

Consider Moog's first voltage
controlled oscillator, the model 901A/B duo. At a list price of several
hundred dollars in 1964, what you got for a 901B VCO was a basic oscillator with
four waveform outputs. If you wanted volts/octave response (which
was essential for any kind of tonal music), you had to also buy the
separate 901A driver module which contained the exponential
converter. And oh by the way, the VCO contained absolutely no
temperature compensation, which meant you had to constantly re-tune
as the circuits warmed up and/or the room temperature varied.

As another example, consider the Moog 904B VCF. Here's a photo of one:

Note that it's a 2U wide module and how big it is and how much empty
space there is on the panel. Why is it so big? Because the circuit
board behind the panel needed to be that big in order to cram all of
the circuitry in. Here's another, more drastic example of that sort of thing:

This is the 905 reverb. Lots of wasted panel real estate? You bet. It's that large because it uses a spring reverb tank, which is mounted in the module itself, right behind the panel. Modern modulars that offer spring reverb modules mount the tank remotely, somewhere in the rear of the case. Although, oddly, the Club of the Knobs reproduction of the 905 retains the same 2U wide panel design, even though it uses remote mounted tanks:

Club of the Knobs C905 reverb. Photo from COTK's Web site.

This is taking authenticity to a bit of an extreme. Clearly, a 1U panel would have been sufficient. The Eurorack users always say that all of the large format modulars take up too much space, and this sort of thing doesn't help.

There were a lot of things about the
Moog modulars that were different from today's modulars and made them
not so easy to interface to or work with. Most Moog VCOs and other
signal generators output a signal that is only 1.5V peak to peak.
This I assume was a choice made based on typical use of signals as
modulation sources, but, for example, it means that the output of a
VCO or an envelope generator can't be made to drive a VCF though its
full frequency range without being amplified. For reasons totally unclear to me, MOS-LAB recently decided to go back to Moog's 1.5V standard for its reproduction of the 901B and 921B VCOs.

And there's the infamous S-trigger
signals. On a Moog modular (and other vintage Moog synths such as
the early Minimoogs), something that generates a trigger or gate
signal does not output a voltage pulse. Rather, the output is a
simple transistor that is saturated in the “low” or “off”
state, shorting the output to ground, or cut off in the “on” or
“high” state, which leaves the output “floating”
electrically. The output expects that whatever trigger/gate input it
is patched to will “pull up” the output by applying a voltage
through a resistor. When the output is in the high state, its
voltage rises to the pull-up voltage; when it is in the low state, it
shorts the output to ground, and the pull-up resistor limits the
current that flows to ground. We've all seen that the modular Moogs
use the infamous “Cinch-Jones” two-bladed connector for trigger
outputs and inputs, requiring a separate type of patch cord to
connect them (and thus the modular Moogs do not have fully unified
patching). This is why; if a trigger/gate input, with its pull-up,
were inadvertently connected to a signal output, it could potentially
damage the output circuit. But it's a pain because of the special cable needed, and because you need an adapter to interface any external trigger or gate source. Mercifully, neither MOS-LAB nor COTK has chosen to use the S-trigger on their Moog reproductions, even though the connector itself is still available.

And last but not least, there's the cost of construction using those "authentic Moog" methods and circuits. As I wrote above, there were a lot of places where the Moog designs had to use methods and techniques that were a lot more expensive (such as building op-amps out of discrete circuitry) because more capable components weren't available at the time. Consider: Synthesizers.com offers two step sequencers -- the Q119 and the Q960. The Q960 is a fairly faithful recreation of the Moog 960 sequencer design, up to and including the incandescent lamps which indicate the active stage (which most users replace with LEDs because the lamps burn out frequently). The Q119, on the other hand, has most of the same capabilities and controls but is microprocessor controlled, and all of the indicator lamp are LEDs. The two share many capabilities -- but the Q119 is about $300 less expensive, plus in order to duplicate the Q119's 24-step mode with the Q960, you need to add a Q962 sequential switch, at an additional $160.

Moog 960 (top) and Synthesizers.com Q119 (bottom). Top photo courtesy of David Brown at modularsynthesis.com; bottom photo courtesy of Synthesizers.com

So given all of the above, I'm starting
to wonder if the current market isn't fetishizing the modular Moogs a
bit much. Of course, the Dotcom/MU format was based on the physical
dimensions of the original Moog modulars, and Roger Arrick's designs
continue to take certain design cues from the Moogs, such as the
black panel background and the knob style. But Arrick started out
with fresh circuit designs using contemporary electronics technology.
And he's no slave to the Moog look and feel; he has never hesitated
to make a module smaller than the functionally equivalent Moog module
when the circuit design allowed for it. The other notable thing was
that Arrick avoided both the weird mix of power supply voltages and
the edge connectors that Moog modules used; Synthesizers.com set the
standard power for the MU format at +/- 15V and +5 volts, and the
flexible power supply harness doesn't limit the modules' board
mounting geometry the way the Moog edge connectors did. (The Dotcom
MTA-100 power connectors are also a lot less prone to corrosion
problems than the Moog edge connectors are.) As for Club of the Knobs, they started out copying the Moog modules, but soon realized that simply duplicating the Moog lineup would be too limiting. And although they continue to stick to the general Moog format, they have long since blown past the limitations of the original Moogs with module designs that Moog could never have thought of or implemented with the technology available at the time, such as the C950A MIDI interface / arpeggiator.

That's why, to be honest, I really
don't want to see a big comeback of slavish Moog-modular clones. Even
putting aside the difficulties of obtaining exact replacements for the
vintage Moog parts, the 1960s Moog modulars were just all-around
limited compared to what is available today. Yes, it's great that
Moog has been able to sell several of the $1.5M copies of the Keith
Emerson modular; the units will instantly be valuable collector's
items as well as being highly educational, and more power to Moog for
being able to build them and sell them at that price. What bothers
me is the people might get the idea that the 5U formats are all about duplicating what has been done in the past, with the implication being that you have to turn to the Euro format to find any modern or fresh ideas. That would be a self-limiting move for 5U. And as someone who wants modern capabilities but prefers to work with 5U formats, I don't want to see that happen.

About Me

Switched-On Bach and Edgar Winter's Frankenstein were my gateways into electronic music. The nature of sound has always fascinated me, and the possibilities of the synthesizer compelled me even before I knew what one was or how it worked. Since then, I've done primitive sampling by splicing cassette tapes, played synth in a bar band, and added funny noises to various art projects. Now, I finally have the studio, the equipment, and the knowledge to make the music I want to make. So what kind of music do I want to make? Read on...